/**
 * @author zz85 / https://github.com/zz85 | twitter.com/blurspline
 *
 * Depth-of-field shader with bokeh
 * ported from GLSL shader by Martins Upitis
 * http://blenderartists.org/forum/showthread.php?237488-GLSL-depth-of-field-with-bokeh-v2-4-(update)
 *
 * Requires #define RINGS and SAMPLES integers
 */



THREE.DOFShader = {

    uniforms: {

        "textureWidth":  { value: 1.0 },
        "textureHeight":  { value: 1.0 },

        "focalDepth":   { value: 50.0 },
        "focalLength":   { value: 20.0 },
        "fstop": { value: 4 }, //

        "tColor":   { value: null },
        "tDepth":   { value: null },

        "maxblur":  { value: 1.0 },

        "showFocus":   { value: 1 },
        "manualdof":   { value: 0 },
        "vignetting":   { value: 0 },
        "depthblur":   { value: 1 },

        "threshold":  { value: 1.0 }, // 这个能够改变感光强度
        "gain":  { value: 2.0 }, // 高光部分的亮度
        "bias":  { value: 0.5 },
        "fringe":  { value: 0.7 },

        "znear":  { value: 0.1 },
        "zfar":  { value: 1000 },

        "noise":  { value: 1 },
        "dithering":  { value: 0.0001 },
        "pentagon": { value: 0 },

        "shaderFocus":  { value: 1 },
        "focusCoords":  { value: new THREE.Vector2(0.5, 0.5) }


    },

    vertexShader: [

        "varying vec2 vUv;",

        "void main() {",

        "vUv = uv;",
        "gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",

        "}"

    ].join( "\n" ),

    fragmentShader: [

        "#include <common>",

        "varying vec2 vUv;",

        "uniform sampler2D tColor;",
        "uniform sampler2D tDepth;",
        "uniform float textureWidth;",
        "uniform float textureHeight;",

        "uniform float focalDepth;  //focal distance value in meters, but you may use autofocus option below",
        "uniform float focalLength; //focal length in mm",
        "uniform float fstop; //f-stop value",
        "uniform bool showFocus; //show debug focus point and focal range (red = focal point, green = focal range)",

        "/*",
        "make sure that these two values are the same for your camera, otherwise distances will be wrong.",
        "*/",

        "uniform float znear; // camera clipping start",
        "uniform float zfar; // camera clipping end",

        "//------------------------------------------",
        "//user variables",

        "const int samples = 4; //samples on the first ring",
        "const int rings = 4; //ring count",

        "const int maxringsamples = rings * samples;",

        "uniform bool manualdof; // manual dof calculation",
        "float ndofstart = 1.0; // near dof blur start",
        "float ndofdist = 2.0; // near dof blur falloff distance",
        "float fdofstart = 1.0; // far dof blur start",
        "float fdofdist = 3.0; // far dof blur falloff distance",

        "float CoC = 0.03; //circle of confusion size in mm (35mm film = 0.03mm)",

        "uniform bool vignetting; // use optical lens vignetting",

        "float vignout = 1.3; // vignetting outer border",
        "float vignin = 0.0; // vignetting inner border",
        "float vignfade = 22.0; // f-stops till vignete fades",

        "uniform bool shaderFocus;",
        "// disable if you use external focalDepth value",

        "uniform vec2 focusCoords;",
        "// autofocus point on screen (0.0,0.0 - left lower corner, 1.0,1.0 - upper right)",
        "// if center of screen use vec2(0.5, 0.5);",

        "uniform float maxblur;",
        "//clamp value of max blur (0.0 = no blur, 1.0 default)",

        "uniform float threshold; // highlight threshold;",
        "uniform float gain; // highlight gain;",

        "uniform float bias; // bokeh edge bias",
        "uniform float fringe; // bokeh chromatic aberration / fringing",

        "uniform bool noise; //use noise instead of pattern for sample dithering",

        "uniform float dithering;",

        "uniform bool depthblur; // blur the depth buffer",
        "float dbsize = 1.25; // depth blur size",

        "/*",
        "next part is experimental",
        "not looking good with small sample and ring count",
        "looks okay starting from samples = 4, rings = 4",
        "*/",

        "uniform bool pentagon; //use pentagon as bokeh shape?",
        "float feather = 0.4; //pentagon shape feather",

        "//------------------------------------------",

        "float penta(vec2 coords) {",
            "//pentagonal shape",
            "float scale = float(rings) - 1.3;",
            "vec4  HS0 = vec4( 1.0,         0.0,         0.0,  1.0);",
            "vec4  HS1 = vec4( 0.309016994, 0.951056516, 0.0,  1.0);",
            "vec4  HS2 = vec4(-0.809016994, 0.587785252, 0.0,  1.0);",
            "vec4  HS3 = vec4(-0.809016994,-0.587785252, 0.0,  1.0);",
            "vec4  HS4 = vec4( 0.309016994,-0.951056516, 0.0,  1.0);",
            "vec4  HS5 = vec4( 0.0        ,0.0         , 1.0,  1.0);",

            "vec4  one = vec4( 1.0 );",

            "vec4 P = vec4((coords),vec2(scale, scale));",

            "vec4 dist = vec4(0.0);",
            "float inorout = -4.0;",

            "dist.x = dot( P, HS0 );",
            "dist.y = dot( P, HS1 );",
            "dist.z = dot( P, HS2 );",
            "dist.w = dot( P, HS3 );",

            "dist = smoothstep( -feather, feather, dist );",

            "inorout += dot( dist, one );",

            "dist.x = dot( P, HS4 );",
            "dist.y = HS5.w - abs( P.z );",

            "dist = smoothstep( -feather, feather, dist );",
            "inorout += dist.x;",

            "return clamp( inorout, 0.0, 1.0 );",
        "}",

        "float bdepth(vec2 coords) {",
            "// Depth buffer blur",
            "float d = 0.0;",
            "float kernel[9];",
            "vec2 offset[9];",

            "vec2 wh = vec2(1.0/textureWidth,1.0/textureHeight) * dbsize;",

            "offset[0] = vec2(-wh.x,-wh.y);",
            "offset[1] = vec2( 0.0, -wh.y);",
            "offset[2] = vec2( wh.x -wh.y);",

            "offset[3] = vec2(-wh.x,  0.0);",
            "offset[4] = vec2( 0.0,   0.0);",
            "offset[5] = vec2( wh.x,  0.0);",

            "offset[6] = vec2(-wh.x, wh.y);",
            "offset[7] = vec2( 0.0,  wh.y);",
            "offset[8] = vec2( wh.x, wh.y);",

            "kernel[0] = 1.0/16.0;   kernel[1] = 2.0/16.0;   kernel[2] = 1.0/16.0;",
            "kernel[3] = 2.0/16.0;   kernel[4] = 4.0/16.0;   kernel[5] = 2.0/16.0;",
            "kernel[6] = 1.0/16.0;   kernel[7] = 2.0/16.0;   kernel[8] = 1.0/16.0;",


            "for( int i=0; i<9; i++ ) {",
                "float tmp = texture2D(tDepth, coords + offset[i]).r;",
                "d += tmp * kernel[i];",
            "}",

            "return d;",
        "}",


        "vec3 color(vec2 coords,float blur) {",
            "//processing the sample",

            "vec3 col = vec3(0.0);",
            "vec2 texel = vec2(1.0/textureWidth,1.0/textureHeight);",

            "col.r = texture2D(tColor,coords + vec2(0.0,1.0)*texel*fringe*blur).r;",
            "col.g = texture2D(tColor,coords + vec2(-0.866,-0.5)*texel*fringe*blur).g;",
            "col.b = texture2D(tColor,coords + vec2(0.866,-0.5)*texel*fringe*blur).b;",

            "vec3 lumcoeff = vec3(0.299,0.587,0.114);",
            "float lum = dot(col.rgb, lumcoeff);",
            "float thresh = max((lum-threshold)*gain, 0.0);",
            "return col+mix(vec3(0.0),col,thresh*blur);",
        "}",

        "vec3 debugFocus(vec3 col, float blur, float depth) {",
            "float edge = 0.002*depth; //distance based edge smoothing",
            "float m = clamp(smoothstep(0.0,edge,blur),0.0,1.0);",
            "float e = clamp(smoothstep(1.0-edge,1.0,blur),0.0,1.0);",

            "col = mix(col,vec3(1.0,0.5,0.0),(1.0-m)*0.6);",
            "col = mix(col,vec3(0.0,0.5,1.0),((1.0-e)-(1.0-m))*0.2);",

            "return col;",
        "}",

        "float linearize(float depth) {",
            "return -zfar * znear / (depth * (zfar - znear) - zfar);",
        "}",


        "float vignette() {",
            "float dist = distance(vUv.xy, vec2(0.5,0.5));",
            "dist = smoothstep(vignout+(fstop/vignfade), vignin+(fstop/vignfade), dist);",
            "return clamp(dist,0.0,1.0);",
        "}",

        "float gather(float i, float j, int ringsamples, inout vec3 col, float w, float h, float blur) {",
            "float rings2 = float(rings);",
            "float step = PI*2.0 / float(ringsamples);",
            "float pw = cos(j*step)*i;",
            "float ph = sin(j*step)*i;",
            "float p = 1.0;",
            "if (pentagon) {",
                "p = penta(vec2(pw,ph));",
            "}",
            "col += color(vUv.xy + vec2(pw*w,ph*h), blur) * mix(1.0, i/rings2, bias) * p;",
            "return 1.0 * mix(1.0, i /rings2, bias) * p;",
        "}",

        // 主函数
        "void main() {",
            "//scene depth calculation",

            "float depth = linearize(texture2D(tDepth,vUv.xy).x);",

            "// Blur depth?",
            "if (depthblur) {",
                "depth = linearize(bdepth(vUv.xy));",
            "}",

            "//focal plane calculation",

            "float fDepth = focalDepth;",

            "if (shaderFocus) {",

                "fDepth = linearize(texture2D(tDepth,focusCoords).x);",

            "}",

            "// dof blur factor calculation",

            "float blur = 0.0;",

            "if (manualdof) {",
                "float a = depth-fDepth; // Focal plane",
                "float b = (a-fdofstart)/fdofdist; // Far DoF",
                "float c = (-a-ndofstart)/ndofdist; // Near Dof",
                "blur = (a>0.0) ? b : c;",
            "} else {",
                "float f = focalLength; // focal length in mm",
                "float d = fDepth*1000.0; // focal plane in mm",
                "float o = depth*1000.0; // depth in mm",

                "float a = (o*f)/(o-f);",
                "float b = (d*f)/(d-f);",
                "float c = (d-f)/(d*fstop*CoC);",

                "blur = abs(a-b)*c;",
            "}",

            "blur = clamp(blur,0.0,1.0);",

            "// calculation of pattern for dithering",

            "vec2 noise = vec2(rand(vUv.xy), rand( vUv.xy + vec2( 0.4, 0.6 ) ) )*dithering*blur;",

            "// getting blur x and y step factor",

            "float w = (1.0/textureWidth)*blur*maxblur+noise.x;",
            "float h = (1.0/textureHeight)*blur*maxblur+noise.y;",

            "// calculation of final color",

            "vec3 col = vec3(0.0);",
            "float alpha = 1.0;",
            "if(blur < 0.05) {",
                "//some optimization thingy",
                "col = texture2D(tColor, vUv.xy).rgb;",
                "if(col.x == 0.0 && col.y == 0.0 && col.z == 0.0) discard;",
            "} else {",
                "col = texture2D(tColor, vUv.xy).rgb;",
                "if(col.x == 0.0 && col.y == 0.0 && col.z == 0.0) discard;",
                "float s = 1.0;",
                "int ringsamples;",

                "for (int i = 1; i <= rings; i++) {",
                    "/*unboxstart*/",
                    "ringsamples = i * samples;",

                    "for (int j = 0 ; j < maxringsamples ; j++) {",
                        "if (j >= ringsamples) break;",
                        "s += gather(float(i), float(j), ringsamples, col, w, h, blur);",
                    "}",
                     "/*unboxend*/",
                "}",

                "col /= s; //divide by sample count",
            "}",

            // "if (showFocus) {",
            //     "col = debugFocus(col, blur, depth);",
            // "}",
            //
            // "if (vignetting) {",
            //     "col *= vignette();",
            // "}",

            "gl_FragColor.rgb = col;",
            "gl_FragColor.a = 1.0;",
        "} "

    ].join( "\n" )

};